1. Field of the Invention
The present invention generally relates to information processing, and more particularly to an information processing apparatus in which a plurality of information processing units are connected to a ring-pattern bus, an information processing method for the information processing apparatus, and a storage medium storing a program thereof.
2. Description of the Related Art
A conventional method for efficiently processing information by performing in parallel processing circuits realized by a hardware uses pipe-line connection of a bus type as discussed in Japanese Patent Application Laid-Open No. 2734246.
According to this method, data, which is input from an external memory via an interface (I/F) at an input end, is sequentially processed according to an order in which a plurality of processing circuits are arranged and is output at an output end to an external memory. Therefore, a processing order is restricted by an order in which the processing circuits are connected when being mounted in the hardware, and cannot be changed.
There is a method for connecting the processing circuits with a ring-pattern bus (hereinafter, referred to as a ring bus) as discussed in Japanese Application Patent Laid-Open Nos. 2522952 and 2834210. Since the processing circuit is connected to the ring bus as a part of the hardware and thus has a fixed processing function, it has been difficult to freely realize a processing order different from a physical connection order of the processing circuit.
For example, a method is discussed for performing the processing while data is being received and transmitted between the plurality of processing circuits by using a communication system of a token passing method.
However, when the processing order different from the connection order is to be realized using such a data path, in the communication path configured in a ring pattern, the data circulating in the ring bus is increased due to a change of the order. As a result, data traffic in the ring bus is increased, thereby decreasing a processing performance and generating deadlocks.